Question $7(5$ points$)$

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Slotted ALOHA is one of the simplest random access protocols that a node always transmits at the full rte of the channel as R bps: when the each node involved in the collision repeatedly retransmits its frame $u$ gets through without a collision:

Suppose four active nodes $($A$,$ B$,$ C and D$)$ are competing for access to slotted ALOHA. Assume each node has an infinite number of packets node attempts to transmit in each slot with probability $p.$ The slot nu as slot $1,$ slot$2,$ slot$3$ and slot$4.$

What is the probability that some node $($either A$,$ B$,$ C or D$)$ succeed